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glass diffusion pumps

[email protected]
 

Hi

I am new here, James Lerch told me about you guys. I have just finished reading the
archives. Interesting and seems like a good resource.

I am busy trying to find parts for a vacuum system for ATM aluminium coating. South
Africa seems to be a little poor on the second hand diffusion pump side. I have
however found a local glass blower who can make a diffusion pump. The inlet would
end up being about one inch. Does anyone have any experience to share.

Please check out the the following

I saw in the archives that someone was looking for design parameters for a pump. If
someone at an academic institution can access this then we may have a source for the
design criteria. I am thinking particularly of the people who live in out of the way places
like South Africa.

I am still asking around for an ultra centrifuge as it may be a little more accessible than
other redundant equipment.

Any other ideas where I may get some old equipment.

Kind regards and nice to meet you folks.

Geoff

Please be patient with me I do tend to talk a bit much
 

Geoff
Welcome, the glass pump looks real sharp It looks like a lot of work
to put it together.
E-bay seems to be where most of us get used stuff.
The workings of most of these pumps seem to be simple so I don't know
that you would need an engineered design, rather just scale some of
the existing sketches and go from there. I would be glad to measure
up one or both of mine but they are very old and I don't know if the
design is obsolete. I have a CVC 6"(I think!)and a varian 3" If you
have access to someone with a wood lathe and metal spinning experence
it may be easer to make one from some soft (1100 )aluminum and pipe.
The glass one does looks nice. How do you cool it?

We all tend to talk to little a bit of chatter would be most
welcome.

Ron White

-
Charles Mitchard
 

Hi Ron,
I would love some dimensions if you have the time.
From what I can see of the glass design it should be simple to build in aluminium or stainless.
Do the chimneys actually sit in the oil or do they sit just above the oil? Thats the sort of questions I have at the moment.
I would use a freezer coil and jacket surrounding the parts requiring cooling to experiment with.
Charles

At 04:04 AM 8/11/03 +0000, you wrote:
Geoff
Welcome, the glass pump looks real sharp It looks like a lot of work
to put it together.
E-bay seems to be where most of us get used stuff.
The workings of most of these pumps seem to be simple so I don't know
that you would need an engineered design, rather just scale some of
the existing sketches and go from there. I would be glad to measure
up one or both of mine but they are very old and I don't know if the
design is obsolete. I have a CVC 6"(I think!)and a varian 3" If you
have access to someone with a wood lathe and metal spinning experence
it may be easer to make one from some soft (1100 )aluminum and pipe.
The glass one does looks nice. How do you cool it?
 

¿ªÔÆÌåÓý

I have been on this list for a while but have never participated.
?
There has been some discussion re dimensions and manufacture of diff pumps.
?
Everything I have read indicates that dimensions are not all that critical.? But then I have not made one to test this out.? Its something I intend to do sometime....
?
With this in mind, I have collected all the information that I could.? Some from books - others from other sources.
?
One interesting source was a Neon Sign maker in Cairns (Australia) who still uses a diff pump.? Apparently his opposition has changed to a Turbo Pump.? But as he points out with some satisfaction, a few drops of mercury accidentally feeding into the Turbo Pump had disasterous concequences - something his old fashioned Diff Pump will take without self destruction.? Apparently this is an ever present hazard with 'Neon' sign work.
?
Anyway, we got talking and it turned out that he takes it apart for a good clean every few years - and so he would not reassemble incorrectly etc he measured and drew the innards.? I think these drawings are a combination of the operating manual with some of his notes and dimensions.
?
?
Needless to say, I got some photocopies.? The quality is marginal but I hope sufficient.? They are on my web site below.? Will only stay there probably for a few weeks only so if any one wants to get copies or put them on another web site do it now.
?
?
?
?
?
?
?
Some of the diff pumps listed on eBay over the last year have shown quite detailed pictures of the inside construction.? I know a lot of people watch this source but when a price has been too high, may not have followed up.? Sometimes it is worth doing this just for the detailed pics.
?
?
I have always intended to make a pump of about this size roughly based on these dimensions - although possibly modified to better suite available materials and my tooling.
?
Anyway, maybe this will be of some use - and if anyone has experience and success with this, I hope they will post ideas and results.
?
For what its worth, I spent time?40 years ago working with a classic glass?Mercury Diffusion pump for some lab experiments.? The dimensions were not that critical.? I can remember helping (mainly watching in admiration) as the resident glassblower made some repairs.? I know Hg diff pumps?aint recommended for a lot of reasons - some quite valid.? But they did the (small)?job then, and I am still here.
?
Hope this is of some use
?
Peter Smith.?
?
?
?
?
?
?
?
?
?
 

Time is a real problem right now I have way to many projects going on but I think I can get the info shortly. the bottom spinning sets flat to the bottom and if memory is correct there are small notches 3 or 4 to allow the oil under it. I think the oil level is what generates the pressure difference to force the vapor to the top. I'll get sketches / photos
?
Ron white

Charles Mitchard wrote:

Hi Ron,
I would love some dimensions if you have the time.
From what I can see of the glass design it should be simple to build in
aluminium or stainless.
Do the chimneys actually sit in the oil or do they sit just above the oil?
Thats the sort of questions I have at the moment.
I would use a freezer coil and jacket surrounding the parts requiring
cooling to experiment with.
Charles

At 04:04 AM 8/11/03 +0000, you wrote:
>Geoff
>Welcome, the glass pump looks real sharp It looks like a lot of work
>to put it together.
>E-bay seems to be where most of us get used stuff.
>The workings of most of these pumps seem to be simple so I don't know
>that you would need an engineered design, rather just scale some of
>the existing sketches and go from there. I would be glad to measure
>up one or both of mine but they are very old and I don't know if the
>design is obsolete. I have a CVC 6"(I think!)and a varian 3"? If you
>have access to someone with a wood lathe and metal spinning experence
>it may be easer to make one from some soft (1100 )aluminum and pipe.
>The glass one does looks nice. How do you cool it?



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I was talking to a guy who was studing physics / vacuum in the 50'S at that time current thinking was that diff pumps would soon not be used anymore because other pumps were faster / eaiser etc. They are still widely used for e-beam welders / furnaces and other 'dirty" applications that would eat turbo pumps.
?
Ron White
Peter John Smith wrote:

I have been on this list for a while but have never participated.
?
There has been some discussion re dimensions and manufacture of diff pumps.
?
Everything I have read indicates that dimensions are not all that critical.? But then I have not made one to test this out.? Its something I intend to do sometime....
?
With this in mind, I have collected all the information that I could.? Some from books - others from other sources.
?
One interesting source was a Neon Sign maker in Cairns (Australia) who still uses a diff pump.? Apparently his opposition has changed to a Turbo Pump.? But as he points out with some satisfaction, a few drops of mercury accidentally feeding into the Turbo Pump had disasterous concequences - something his old fashioned Diff Pump will take without self destruction.? Apparently this is an ever present hazard with 'Neon' sign work.
?
Anyway, we got talking and it turned out that he takes it apart for a good clean every few years - and so he would not reassemble incorrectly etc he measured and drew the innards.? I think these drawings are a combination of the operating manual with some of his notes and dimensions.
?
?
Needless to say, I got some photocopies.? The quality is marginal but I hope sufficient.? They are on my web site below.? Will only stay there probably for a few weeks only so if any one wants to get copies or put them on another web site do it now.
?
?
?
?
?
?
?
Some of the diff pumps listed on eBay over the last year have shown quite detailed pictures of the inside construction.? I know a lot of people watch this source but when a price has been too high, may not have followed up.? Sometimes it is worth doing this just for the detailed pics.
?
?
I have always intended to make a pump of about this size roughly based on these dimensions - although possibly modified to better suite available materials and my tooling.
?
Anyway, maybe this will be of some use - and if anyone has experience and success with this, I hope they will post ideas and results.
?
For what its worth, I spent time?40 years ago working with a classic glass?Mercury Diffusion pump for some lab experiments.? The dimensions were not that critical.? I can remember helping (mainly watching in admiration) as the resident glassblower made some repairs.? I know Hg diff pumps?aint recommended for a lot of reasons - some quite valid.? But they did the (small)?job then, and I am still here.
?
Hope this is of some use
?
Peter Smith.?
?
?
?
?
?
?
?
?
?


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VacuumX-unsubscribe@...



Your use of Yahoo! Groups is subject to the .

nano_tronics
 

--- In VacuumX@..., RON WHITE <ron_white@s...> wrote:
Time is a real problem right now I have way to many projects going
on but I think I can get the info shortly. the bottom spinning sets
flat to the bottom and if memory is correct there are small notches 3
or 4 to allow the oil under it. I think the oil level is what
generates the pressure difference to force the vapor to the top. I'll
get sketches / photos

Ron white

Charles Mitchard <charlesmitchard@i...> wrote:
Hi Ron,
I would love some dimensions if you have the time.
From what I can see of the glass design it should be simple to
build in
aluminium or stainless.
Do the chimneys actually sit in the oil or do they sit just above
the oil?
Thats the sort of questions I have at the moment.
I would use a freezer coil and jacket surrounding the parts
requiring
cooling to experiment with.
Charles

At 04:04 AM 8/11/03 +0000, you wrote:
Geoff
Welcome, the glass pump looks real sharp It looks like a lot of
work
to put it together.
E-bay seems to be where most of us get used stuff.
The workings of most of these pumps seem to be simple so I don't
know
that you would need an engineered design, rather just scale some of
the existing sketches and go from there. I would be glad to measure
up one or both of mine but they are very old and I don't know if
the
design is obsolete. I have a CVC 6"(I think!)and a varian 3" If
you
have access to someone with a wood lathe and metal spinning
experence
it may be easer to make one from some soft (1100 )aluminum and
pipe.
The glass one does looks nice. How do you cool it?

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some time ago on the net i saw a site witch talked about plans to
make your own VD pump out of ordinary threaded steel or copper pipes
and fittings and performed quite good especialy from out of standard
plumbing stuff, i cant remember what magazine it was all i know that
it was a monthly science mag like american scientist or amateur
scientist or something like that

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